1. Field of the Invention
The invention resides in the field of ground based transportation systems for passenger or freight and more particularly relates to apparatus for the programmable control of an electric vehicle.
2. Description of the Prior Art
This invention relates to an improvement in the transportation system concept disclosed in U.S. Pat. No. 3,687,082 by the same applicant. The method and apparatus employed in that system provide for vehicle speed control by the sequential application of multiple electrical power sources at varying frequencies to an electric motor used to power the vehicle.
The vehicle receives power sequentially from a plurality of groups of busses connected to power supplies which generate a programmed succession of power waves of varying frequencies.
The busses are reached through a vehicle connector extension or pickup, a brush or rotary device for example. As the vehicle moves forward, separate insulated busses are continually contacted and the propulsion motor responds to each contact depending upon the power frequency encountered. The design parameters of motor, power supply frequency, buss spacing, and vehicle speed are selected to bring about a desired result of vehicle mobility pattern.
In particular, the power frequency supplied to each buss is sequentially varied such that, if the vehicle moves continually at a desired speed, it is always supplied with power of a frequency that results in the motor providing sufficient torque to maintain synchronous velocity. If the vehicle slows down or speeds up as a result of grade or load changes it will encounter a power frequency which will cause it to run faster or slower as the case may be. As the velocity of the vehicle adjusts, the motor will again synchronize with a power source frequency that will result in a desired rate of travel.